The present invention relates to large screen high resolution video displays for displaying a large and bright video image, for example, for public entertainment, industrial shows, computer image displays and other uses.
During 1985 a number of companies, mainly in Europe, have started marketing arrays of CRT-based (cathode ray tube) video monitors mounted in a variety of matrix geometries, such as 4.times.4 (whose overall image may be 6.6 feet by 5.0 feet), 3.times.3, 2.times.2, and also larger arrays involving as many as 200 or more monitors. The audience views directly the front faces of the video monitors. These video array systems are capable of creating multi-image effects involving the entire matrix of CRT's using electronic digital image processing circuits. The user may present a single image covering the entire array or the same image on each individual CRT, or any combination of image/CRT displays. Examples of such video array systems are as follows: The "Vidiwall" (TM) of Philips of Holland, which is driven by a laser videodisk system using a large number of laser videodisks; a system marketed by TC Studios of West Germany, whose video array is driven by a 3/4" VTR (video tape recorder); a system marketed by Nurnberger Medientechnik GmbH (Tele-Wall Delcom 256 Model) of West Germany, also operated by 3/4" VTR on laser disks; and systems marketed by Electrosonic ("Videowall" TM) of Minneapolis, Minn. Electrosonic markets video systems which are both 3/4" VTR or laser video disk sources. Furthermore, there are several custom-made systems in various places, mainly discotheques, around the United States and Europe.
In general, those video array systems have various shortcomings. When the array of monitors is positioned side-by-side and on top of each other to form a closely packed matrix, there are mechanical limitations as to how close the video images displayed on each monitor can be moved to each other. Even when closely packed together, there is a dark seam between the images formed on the monitors. That seam is formed by the front edge frames of the video monitors. Using the flattest and squarest CRT's presently available, this seam width is still at least two inches (50.8 cm) between adjacent monitors and around each monitor image. In such arrays of CRT's, there are seams between the various sections of the overall image, so that the image appears as if it originated behind a grill. Another shortcoming of a number of existing systems is that they are operated through computer controlled laser disk programming. To produce a "master" suitable for laser disks and then to produce programs on laser disks is both expensive and time-consuming. In some array systems each monitor is operated by its own laser video disk system, which is expensive and difficult to operate. Other shortcomings relate to the quality of the video image.
A video array system, without seams and with relatively inexpensive electronics, for digital image processing from a VTR/VCR (video cassette recorder) would have technical and commercial advantages over the above-described systems. In displays used for entertainment, merchandising, computer image display and business presentations, it is important that the final image, seen by the audience, be without seams and that the display may be programmed using a relatively inexpensive single video source, such as a single VTR/VCR, a video camera or computer sources, instead of laser video disks. Other advantages with commercial merit involve image quality, image enhancement, elimination of monitor drift, jitter and over-scanning, and brightness.